Bacterial flora in the duodenum of healthy cats, and effect of dietary supplementation with fructo-oligosaccharides

Abstract

Objective - To investigate changes in the duodenal flora of healthy cats over time, and evaluate the effect of dietary supplementation with fructo-oligosaccharides (FOS). Animals - 12 healthy, barrier-maintained, specific-pathogen-free cats. Procedure - Duodenal juice for bacteriologic examination was collected via oral endoscopy 5 times from each cat over a 32-week period. Cats were allotted randomly to 2 groups, and a crossover design study, during which they were fed either a replete dry (basal) diet or, for 12 consecutive weeks, basal diet supplemented with 0.75% FOS, was done. Samples (3 from cats fed the basal and 2 from cats fed the FOS diet) were collected for a minimum of 6 weeks after commencement of feeding, and a minimum of 6 weeks apart. Results - Mean aerobic, anaerobic, and total bacterial counts did not differ significantly among sample collection times. After pooling of the results, mean (± SD) log10 colony-forming units (CFU) of aerobic, anaerobic, and total bacteria/ml were 5.5 ± 1.1, 4.8 ± 1.0 and 5.6 ± 1.1, respectively. However, individual cats had considerable variation in counts: mean (range) intraindividual coefficients of variation were: 19.0 (6.1 to 34.2), 19.9 (4.8 to 35.5), and 18.1 (5.5 to 32.6)%, respectively. In 1 cat, total bacterial count varied between < 3.0 and 6.3 CFU/ml. Bacterial flora varied qualitatively: only Enterococcus faecalis, Clostridium perfringens, Bacteroides, Pasteurella, and Streptococcus spp, and unidentified gram-negative (aerobic) rods were present in > 50% of the samples. Conclusions - Wide quantitative and qualitative variation in the duodenal flora of healthy cats was observed over time, which was not affected by dietary supplementation with FOS.